You might interpolate in between the time steps by yourself: Taking the results of two time steps (e.g. temperature profile on a surface), interpolate the results to your desired time step) e.g. with matlab) and plot the data with any plotting software (matlab, or maybe even Fluent could read that profile).
But I think, this could be very difficult... And might work only for a 2D problem...

Another option: if the time steps are not equal... just change the duration of the images appear in the movie.
like: time step is 1 second -> image duration is 1 second,
time step is 2 seconds -> image duration is 2 seconds (or use that image twice for each 1 second)
For that, you have to find the least common denominator of the time step size....

you might write a journal, that sets different time steps (e.g. first 80 time steps with 0.1 seconds, than 60 time steps with 0.5 seconds and finally 60 time steps with 1 second, 10 iteration each time step).

we are running the adaptive iteration up to a time value that we define as "End Time" and when the iteration stops, by using text commands we open a new window, display the contours (or anything else), take hardcopy of the window and we close it. Then we continui iterating with a new value of end time and so on.

my colleague wrote a VBA code to write a journal file with all the text commands and now we are able to take images (in tiff format directly) at the intervals we define.